/** @apilevel internal */
 private HashMap methodsSignatureMap_compute() {
   HashMap map = new HashMap(localMethodsSignatureMap());
   for (Iterator outerIter = superinterfacesIterator(); outerIter.hasNext(); ) {
     TypeDecl typeDecl = (TypeDecl) outerIter.next();
     for (Iterator iter = typeDecl.methodsIterator(); iter.hasNext(); ) {
       MethodDecl m = (MethodDecl) iter.next();
       if (!m.isPrivate()
           && m.accessibleFrom(this)
           && !localMethodsSignatureMap().containsKey(m.signature()))
         putSimpleSetElement(map, m.signature(), m);
     }
   }
   for (Iterator iter = typeObject().methodsIterator(); iter.hasNext(); ) {
     MethodDecl m = (MethodDecl) iter.next();
     if (m.isPublic() && !map.containsKey(m.signature()))
       putSimpleSetElement(map, m.signature(), m);
   }
   return map;
 }